Best All-in-One Device for Vehicles?

My buddy spent like $40 on a backup cam system for his truck, and I kind of feel bad for him. Couldn't he get something more in the $100 range that would also hookup to a camera, and also be usable as a dedicated GPS unit until reverse gear is detected somehow?

And why stop there, with the badass NUCs and budget tablets that are coming out these days it could probably play music receive incoming texts & convert them to audio, etc as well.